Apparatus for positioning grinding disks



Oct. 6, 1964 v H. J. FALLON 1,

APPARATUS FOR POSITIONING GRINDING DISKS Original Filed Nov. 24, 1959 2 Sheets-Sheet 1 INVENTOR.

Oct. 6, 1964 H. J. FALLON 3,151,422

APPARATUS FOR POSITIONING GRINDING DISKS Original Filed Nov. 24-, 1959 2 Sheets-Sheet 2 mmvron.

United States Patent 3,151,422 APPARATU FUR PGSITIGNING GRENDDJG DISKfi Herbert 3. Fallon, iieioit, Wis assignor to Beasley-Welles Corporation, South Beloit, iii, a corporation of Iliinois Griglnal application Nov. 24, 1959, Ser. No. 855,051, now

Patent No. 3,679,740, dated Mm. 5, 1963. Divided and this application Aug. 15, 1962, Ser. No. 224,267

6 Claims. {CL 51-I65) This is a division of application Serial No. 855,051, filed November 24, 1959, now Patent No. 3,079,740, issued March 5, 1963.

This invention is in the field of grinders and is concerned with sizing devices for accurately positioning a grinding wheel in a disk grinder or the like.

A primary object of the invention is a sizing device which does not require physical contact with the faces of the grinding disk in a disk grinder.

Another object is a gauging device which uses an air jet to sense the position of the face of the disk.

Another object is a nozzle which is movably mounted in a double disk grinder so that the disks may be moved in somewhat preparatory to a dressing operation.

Another object is a gauging arrangement for double disk grinders which is particularly beneficial for or with an automatic dresser.

Another object is a gauging arrangement which senses the disk face in an accurate location.

Another object is a gauging or sizing arrangement which may be used with a rotary, oscillating, through feed, or any suitable feeding mechanism.

Other objects will appear from time to time in the ensuing specification and drawings in which:

FIGURE 1 is a schematic or diagrammatic layout of the invention;

FIGURE 2 is a perspective of a portion of the grinder;

FIGURE 3 is a side view, on an enlarged scale, of the air nozzles previously shown schematically; and

FIGURE 4 is a section along line 44 of FIGURE 3.

In FIGURE 1, the disks of a double disk grinder have been shown opposite each other spaced apart a predetermined distance so that the workpieces may be passed between the disks to grind accurate parallel opposite surfaces by direct contact with the disk faces 12. The disks are mounted on shafts 14 and are rotated by any suitable drive. Nor is the make-up of the specific grinding disks important, other than that they may be suitable abrasive grinding wheels.

I show two air nozzles or jets 16 positioned between the grinding disks, back to back, with openings so that the air jets from the nozzles wfll be directed in opposite directions. It will be noted in FIGURE 1 that the nozzles are opposite the faces of the disks and the air jets from the nozzles will strike or impinge against the faces 12 of the disks. The nozzles are mounted on a suitable support 18 and are supplied with air through suitable conduits or tubes 20 from controllers 22. Air from the air source, such as a compressor or the like, not shown, is supplied to each of the controllers by suitable connections 24 and the air is monitored or controlled by the controller and in turn is passed through the tubes 20 to the nozzles 16. The controllers may be of the type presently sold by Moore Products Company of Philadelphia, Pennsylvania and, in detail, are not important to this invention. Suffice it to say that the controller basically senses the variations in a pressure signal and converts it to an electrical signal by operating switch contacts or the like. The controllers sense the pressure of the air passing through the system to the nozzles and in response to that pressure control the infeed of the grinding disks toward each other. It will be noted in FIGURE 1 that the grinding disks are constructed to be moved toward each other as the faces ice wear away during grinding, such movement being indicated by arrows. The controllers each send a signal to the disk feeding mechanism, to be set forth more in detail hereinafter, through suitable leads 26. The controllers may be supplied with current through suitable leads 27 from an outside power source.

Workpieces are passed between the faces 12 of the grinding disks. As the disks break down or wear away, the faces will move farther and farther away from the jet outlets of the nozzles 16. This reduces the resistance to the outflow of air from the nozzles thereby causing the pressure of the air in the system to drop. The controllers can be set up so that in response to a predetermined low pressure, a signal will be sent through electric leads or otherwise, to the infeeding mechanism which will move either one or both disks toward each other. As the disk face approaches the nozzle opening, it will offer more resistance to the air flow. This will cause the air pressure in the system to increase. A controller may be set up so that at a predetermined high pressure the infeed will cease.

The grinding wheel infeed mechanism may be set so that in response to a signal from the controller, it will automatically infeed a set amount. As soon as the air pressure in the system drops to a predetermined low, the controller will send a signal to the infeed mechanism causing it to infeed a predetermined amount. The infeed of the wheel face will cause the air pressure in the system to rise, and if it rises above a desirable minimum or within a preset range, no further infeeding will be necessary. But if it is still below, the controller will again send a signal causing another infeed until the desirable spacing is obtained.

In FIGURE '2, one of the disks It) is shown with its nozzle 16, it being understood that the showing in FIG- URE 2 could be either disk of FIGURE 1. The disk is rotatably mounted in a quill 28 and is driven by a drive 30 which leads to an electric motor or the like, not shown. The quill is constructed to be moved axially by cylinders 32 which traverse it in an axial direction rapidly back and forth between grinding and dressing positions. As shown in FIGURE 1, the wheels are in grinding position and are closely spaced. When the wheels have broken down sutficiently so that dressing is required, the quills are moved outwardly a predetermined amount by the quill cylinders 32 and a dresser with oppositely disposed diamonds, not shown, is passed between them to dress olf the face of each wheel. I prefer that the two quill cylinders lie in a horizontal plane which passes through the center of the disk and spindle 14 so that the reactive forces will be counterbalanced. The quill is supported by and is constructed to slide back and forth on suitable pads 34. Since the drive 30 is intended to be stationary, I connect it to the projecting end of the disk spindle by a spline connection as.

Mounted above the quill and connected firmly to it by a key connection or the like is a spindle lug or bracket 36 which supports an air cylinder 49. The infeed mechanism 42 is suitably supported by the frame of the machine and includes a cross shaft 44 constructed to be rotated by an automatic ratchet or clutch mechanism and drive 46 or the like connected by leads 26 to the controller 22 to move a feed screw 48 through a suitable gear, pinion, and nut arrangement 50. Rotation of the cross shaft 44 causes the worm gear or rack 48 to move to the left in FIGURE 2 thereby moving bracket 38, quill 28 and the disk It? axially toward the air nozzle 16. The feed screw 48 has a collar 52 which abuts a block 54 connected to the piston rod 56 of the air cylinder 40. Thus, the air cylinder 49 raises and lowers the block 54 to either position in between the bracket 33 and the collar 52 or to raise it above the collar 52 so that the quill cylinders 32 may move the quill and the grinding disk outwardly until the face of bracket 3b contacts the collar 52:.

During normal operation, air pressure is supplied to I the quill cylinders 32 so that they are thrusting outwardor tend to pull the disks outwardly away from grind- This eliminates y ing position and away from each other.

all backlash in the infeed mechanism 42. When the disk feed mechanism and the air cylinder can easily raise the block 52. Then the air pressure in the quill cylinders 32 is again reversed and since the block is up and out of the way the quill will move outwardly until the face of the bracket 38 contacts the collar 52 on the feed mechanism. Then the automatic dresser, not shown, passes between the grinding disks across the disk faces to dress them. Then the air pressure is again reversed in the quill cylinders to bring the quill and the grinding disks back to grinding position where they are more closely spaced and normal grinding starts again.

During normal operation, the air nozzles are quite close to the faces of the disks. For example, they might be at .005 inch. Since the quill cylinders are initially reversed to allow the block 54 to be raised, there is some inward movement of the disks which may be on the order of 7 or 8 thousandths of an inch. To prevent the face of the disk from contact of the nozzle, 1 mount the nozzle so that it will also move inwardly or in the same direction as the movement of the disk, as shown in detail in FIG- URES 3 and 4. A suitable mounting bracket 58 on the frame of the grinder may have a nozzle 60 connected to it by'a suitable cap 61 and mounting bracket 62 held by bolts 64 or otherwise. The second nozzle structure 66 may be mounted on the lower surface of mounting bracket 62 by a mounting bracket 63 and cap 70 connected by bolts 72 or the like. It will be noted that the upper part 73 of mounting bracket 68 is in a guideway 74 on the lower surface of the upper mounting bracket 62 and is constructed to be adjusted longitudinally in any suitable manner and held, when in position, by a bolt and slot connection indicated generally at 75.

The nozzle structure, shown in detail in FTGURE 4 includes an air cylinder 76 having a piston rod 78 extending from it. End caps 80 and 82 are separated by a sleeve type spacer 84 and are connected to it by bolts 86. The end caps 80 and 82 carry spacing pins 8% which are adjustably positioned on each side of a stop plate 90. The outer ends of the pins 88 are beveled and engage adjustable stop screws ?2 which vary the position of the spacing pins 88. Stop plate 90 is against a shoulder 94 on the piston rod 7 8 and is held in place by a key 95. The stop plate fl t fits over a pin 96 mounted in the end cap 82 and slides back and forth on it. This prevents the piston rod 78 from rotating. The other end of the piston rod 78 supports a holder 98 for the air nozzle 16 which is keyed to it at 104). Thus, the holder 98 and air nozzle 16 will be held in position. The end of the piston rod '78 has a suitable cap nut 202 screwed to it and a bellows or diaphragm 104, held on each side by suitable O-rings res, allows for movement of the piston rod 78 and air nozzle 16 and holder 93 without leakage.

It will be noted that a slight spacing exists, as at 119, between the faces of the stop pins 88 and the stop plate 99. This is to say that the faces of the pins 88 are spaced just slightly farther apart than the thickness of the stop plate 90. Thus, the piston rod 73 can move back and forth by an amount equal to the spacing 11o. Movement of the piston rod 78 will move the nozzle holder 98 which in turn moves the nozzle 16.

The structure shown and described in relation to FIG- URE 4 may be the same for both nozzle holders, al-

though it has been specifically set forth with reference to the upper nozzle in FIGURE 3.

Relating the FIGURES 3 and 4 structure to the FIG- URES l and 2 structure, the air cylinder 76 for moving the nozzle 16 may be tied into or related directly or indirectly to the air system for the quill cylinders 32. or it may be separate but operated simultaneously with it. In any event, when the pressure in the quill cylinders 32 is reversed from what it is during grinding, so that the disks are thrust inwardly, at the same time the air in cylinder 76 is reversed so that the piston rod 78 moves to the right in FIGURE 4 and the air nozzle 16 also moves. In the position shown in FIGURE 4, the air cylinder 75 is pulling the nozzle 16 to the left, which may be assumed to be either grinding position or the position assumed at the beginning of a dressing operation.

The use, operation and function of the invention are as follows:

Whereas I have referred principally to a double disk grinder, it should be understood that many, if not all, of the novel features may be applied equally as well to a single disk grinder. Whether single or multiple, the axis of the disk or disks may be vertical, horizontal, or otherwise. Also, I have stressed automatic dressing, and it should be understood that the dressing may be any suitable manual arrangement or semi-automatic. Additionally, the infeed of the disk or disks has been characterized as automatic, and it should be understood that it could be manual. In this sense, the signal from the controller or controllers could energize a suitable light, bell, or any suitable manifesting device in response to which the operator could manually infeed, or energize the infeed mechanism. Or any combination of the above could be used.

While the movable nozzles shown in FIGURE 4 are intended primarily to be used in conjunction with automatic dressing, it should be understood that the nozzles in FIGURE 1 could be adjustably mounted, to be adjusted by hand and preset for any particular grinding operation. But when grinding or dressing, the nozzle or nozzles would be considered fixed. This is true of either a single or multiple disk grinder.

In the past, an air nozzle has been used against the periphery of the grinding wheel in a centerless grinder, but the nozzle was moved toward the grinding wheel, as the wheel broke down, along with a regulating or work positioning wheel. This could not be used in a disk grinder since it would involve a complete overhaul of the article feeding mechanism, be it a rotary or through feeder or what have you, as Well as extreme complication in adjusting the related mechanism.

Accurate positioning of the grinding wheels has proved particularly troublesome in the past. This is particularly true of double disk grinders in which the sides or faces of the wheels are used for grinding instead of the periphery. The faces are closely spaced and are opposite each other and the work may be sheared or passed between the grinding faces. As the faces break down, the wheels are fed inwardly toward each other to compensate for wheel Wear.

In the past, hardened feeler fingers or indirect measuring gauges have been used to feel or sense the position of the wheel face followed by some sort of an infeeding mechanism to compensate for wheel wear. But this in volves physically touching the Wheel face which inevitably results in wear on the item being contacted or in some indirect method such as gauging the workpiece or otherwise.

I would prefer that the air nozzles be located well within the periphery of the grinding disks, for example on the order of 1 /2 inches so that the jets will impinge against the disk faces beyond or inside of the area at the peripheral edge which is broken down rapidly due to shearing in of the workpieces. l also prefer that the nozzles be positioned behind or on the back side of the disks, relative to the side where the workpieces are introduced, and below the center line of the disks. This might be referred to as in the rear lower quadrant. The point is that in a double disk grinder, the disks may be tilted back slightly in the case of a push-through feeder, and tilted both back and down in the case of a rotary feeder. In either case, the rear lower quarter is affected the least and, accordingly, any such tilting or a combination thereof would have the least effect in the rear lower quarter of the disks.

In a double disk grinder where automatic dressing is highly desirable, gauging directly from the wheel faces is very important since once the gauging devices have been set, the dresser can be accurately positioned relative to the nozzles so that when the dresser is passed between the grinding faces, the machine, so to speak, will know exactly where the new faces of the wheels are. Or the nozzles can be set accurately relative to the dresser. But in either case when the faces of the disks have been dressed off, the new plane of the faces will be accurately established relative to some fixed part of the machine. In systems which gauge or check the workpiece, the spacing between the wheel faces may be checked by gauging the workpiece and when oversize, infeeding may take place. But an oversize workpiece does not tell whether or not the wheels have broken down at the same rate or differentially. in the event that one wheel has broken down much faster than the other, an automatic dresser would remove a substantial amount from the wheel that hadnt broken down and might miss or barely touch the other. But, in the arrangement shown, the dresser and nozzle can be accurately positioned relative to each other. Then the wheels can always be brought to the air nozzles or may be positioned in predetermined relation to the air nozzles just prior to an automatic dressing operation. This insures that the dresser will dress approximately the same amount off of each wheel. The dresser referred to above is of the type having oppositely disposed diamonds or the like spaced a predetermined distance apart and the dresser has not been shown in detail in the drawings since it is well known in the art.

While I have referred to the use of two nozzles, each of which checks the face of its wheel independently, it is quite feasible to use one nozzle and thereafter the workpiece could be gauged or checked which would accurately tell the precise position of the face of the other wheel.

In the arrangement shown, the nozzles are also movably mounted so that when the thrust of the quill cylinders is reversed at the beginning of a dressing operation, the nozzles will move in the same direction to prevent contact between the face of the wheels and the nozzles. This has the distinct advantage that in a machine of the type shown backlash may be eliminated during grinding, automatic dressing may be used, and the nozzles may be positioned between the grinding faces of the disks or wheels, all without needless complication with all parts operating or being tied in together.

While I have shown and described the preferred form and suggested variations of my invention, it should be understood that suitable additional modifications, changes, substitutions and alterations may be made without departing from the inventions fundamental theme. I,

therefore, wish that the invention be unrestricted, except as by the appended claims.

I claim:

1. In a double disk grinder, a frame, a pair of opposed grinding disks mounted thereon opposite each other, means for feeding the disks axially toward each other, nozzles disposed between the disks, one for each disk face, an air system connected to each nozzle for supplying pressure air thereto so that an airstream will be directed against the face of each disk from its nozzle, a control device responsive to the pressure of the air in the air system and arranged to feed either disk toward the other in response to a predetermined low pressure in its nozzle, and to cease the infeed in response to a predetermined high pressure in its nozzle, each nozzle being mounted to be moved in a direction generally parallel to the axisof the grinding disks, and power means for moving each nozzle axially away from the face of its grinding disk to prevent contact therewith, said power means being responsive to controlled operation of the grinder when the disks are moved toward each other past the point where the air pressure in the nozzles reaches the predetermined high pressure.

2. The structure of claim 1 further characterized by and including adjustable stops on the frame for determining the extremes of movement of the nozzles.

3. In a grinder, a frame, a grinding disk mounted for rotation thereon, means for feeding the disk axially to compensate for wear, a nozzle disposed opposite the face of the disk, an air system connected to the nozzle for supplying pressure air thereto so that an airstream will be directed against the face of the disk, a control device responsive to a predetermined low air pressure to initiate an infeed operation, the nozzle being movably mounted in an axial direction relative to the disk, and means for moving the nozzle axially away from the disk face during the operative cycle of the grinder when the disk is fed toward the nozzle a distance such that it would otherwise contact the nozzle.

4. The structure of claim 3 further characterized by and including means for preliminarily adjusting and positioning the nozzle in relation to a fixed part of the grinder.

5. The structure of claim 3 further characterized in that the feeding means for the disk is manually controlled.

6. The structure of claim 3 further characterized in that the grinder is a double disk grinder and has two coaxially mounted oppositely disposed disks, each disk having a feeding means, the control device being responsive to the pressure of the air and arranged to energize the feeding means to feed the disks toward the nozzle in response to a predetermined low pressure and to cease the infeed in response to a predetermined high pressure.

References Cited in the file of this patent UNITED STATES PATENTS 517,643 Church Apr. 3, 1894 1,985,576 Mennesson Dec. 25, 1934 2,639,562 Balsiger May 26, 1953 FOREIGN PATENTS 119,068 Sweden June 17, 1947 

1. IN A DOUBLE DISK GRINDER, A FRAME, A PAIR OF OPPOSED GRINDING DISKS MOUNTED THEREON OPPOSITE EACH OTHER, MEANS FOR FEEDING THE DISKS AXIALLY TOWARD EACH OTHER, NOZZLES DISPOSED BETWEEN THE DISKS, ONE FOR EACH DISK FACE, AN AIR SYSTEM CONNECTED TO EACH NOZZLE FOR SUPPLYING PRESSURE AIR THERETO SO THAT AN AIRSTREAM WILL BE DIRECTED AGAINST THE FACE OF EACH DISK FROM ITS NOZZLE, A CONTROL DEVICE RESPONSIVE TO THE PRESSURE OF THE AIR IN THE AIR SYSTEM AND ARRANGED TO FEED EITHER DISK TOWARD THE OTHER IN RESPONSE TO A PREDETERMINED LOW PRESSURE IN ITS NOZZLE, AND TO CEASE THE INFEED IN RESPONSE TO A PREDETERMINED HIGH PRESSURE IN ITS NOZZLE, EACH NOZZLE BEING MOUNTED TO BE MOVED IN A DIRECTION GENERALLY PARALLEL TO THE AXIS 